(1) Field of the Invention
This invention relates to a method for sampling flying insect populations.
(2) Description of the Prior Art
Heretofore, it has not been known that the use of low-frequency sound could be used to detect flying insects. More specifically, the use of low-frequency sound detection to detect and count flying insects in conjunction with a biologically active sex-attractant chemical to lure and bait an agricultural area so that the sound detection device might work is new in the field of insect population sampling.
Flying moths have been caught and counted by entomologists in various types of insect survey traps for more than 40 years. The most popular traps have been equipped with bulbs that emit attractive electromagnetic (light) wavelengths, including blacklight, or traps baited with sex attractants from live insects or from synthetic chemical dispensers. Insects also have been detected by various high power ground-based radar installations and their dispersal tracked by continuously monitoring the coordinants of radar echos from the insect targets. Most of the radar equipment used to detect insects to date is ultra high frequency (.lambda.=3 to 15 cm), high powered in the kilo or megawatt region, and insect detection is only incidental to the proprietary operation of the radar installations.
A system was needed to automatically detect flying insects responsive to sex attractants that otherwise might not be caught in traps. Effectiveness of chemical sex attractants used as bait in insect traps is dependent upon the biological attractive potency of the chemical, dispersion characteristics of the chemical, and response behavior of the insect including flight patterns. All of these factors influence the overall performance of a particular pheromone lure/bait as does the bait's design. No lure baited with pheromone or equipped with an attractive light source can be expected to attract every insect that may respond since insects respond through a gradient of behaviourisms. For example, male tobacco budworm moths [Heliothis virescens (F.)] responsive to a pheromone source may fly toward and land several feet from a pheromone dispenser in a trap, or they may not physically react at all for a given night, or they may fly to the attractive source as they become attracted by the lure.